// BuildConfigFromFlags is a helper function that builds configs from a master
// url or a kubeconfig filepath. These are passed in as command line flags for cluster
// components. Warnings should reflect this usage. If neither masterUrl or kubeconfigPath
// are passed in we fallback to inClusterConfig. If inClusterConfig fails, we fallback
// to the default config.
func BuildConfigFromFlags(masterUrl, kubeconfigPath string) (*rest.Config, error) {
if kubeconfigPath == "" && masterUrl == "" {
glog.Warningf("Neither --kubeconfig nor --master was specified. Using the inClusterConfig. This might not work.")
kubeconfig, err := rest.InClusterConfig()
if err == nil {
return kubeconfig, nil
}
glog.Warning("error creating inClusterConfig, falling back to default config: ", err)
}
return NewNonInteractiveDeferredLoadingClientConfig(
&ClientConfigLoadingRules{ExplicitPath: kubeconfigPath},
&ConfigOverrides{ClusterInfo: clientcmdapi.Cluster{Server: masterUrl}}).ClientConfig()
}
// NewInClusterClient returns a new Kubernetes client that expect to run inside the cluster
func NewInClusterClient() (Client, error) {
config, err := rest.InClusterConfig()
if err != nil {
return nil, err
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
return nil, err
}
return &clientImpl{
clientset: clientset,
}, nil
}
// New creates a new Kubernetes discovery for the given role.
func New(l log.Logger, conf *config.KubernetesSDConfig) (*Kubernetes, error) {
var (
kcfg *rest.Config
err error
)
if conf.APIServer.URL == nil {
kcfg, err = rest.InClusterConfig()
if err != nil {
return nil, err
}
} else {
token := conf.BearerToken
if conf.BearerTokenFile != "" {
bf, err := ioutil.ReadFile(conf.BearerTokenFile)
if err != nil {
return nil, err
}
token = string(bf)
}
kcfg = &rest.Config{
Host: conf.APIServer.String(),
BearerToken: token,
TLSClientConfig: rest.TLSClientConfig{
CAFile: conf.TLSConfig.CAFile,
},
}
}
kcfg.UserAgent = "prometheus/discovery"
if conf.BasicAuth != nil {
kcfg.Username = conf.BasicAuth.Username
kcfg.Password = conf.BasicAuth.Password
}
kcfg.TLSClientConfig.CertFile = conf.TLSConfig.CertFile
kcfg.TLSClientConfig.KeyFile = conf.TLSConfig.KeyFile
kcfg.Insecure = conf.TLSConfig.InsecureSkipVerify
c, err := kubernetes.NewForConfig(kcfg)
if err != nil {
return nil, err
}
return &Kubernetes{
client: c,
logger: l,
role: conf.Role,
}, nil
}
// NewInClusterClientWithEndpoint is the same as NewInClusterClient but uses the provided endpoint URL
func NewInClusterClientWithEndpoint(endpoint string) (Client, error) {
config, err := rest.InClusterConfig()
if err != nil {
return nil, err
}
config.Host = endpoint
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
return nil, err
}
return &clientImpl{
clientset: clientset,
}, nil
}
func main() {
// creates the in-cluster config
config, err := rest.InClusterConfig()
if err != nil {
panic(err.Error())
}
// creates the clientset
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
for {
pods, err := clientset.Core().Pods("").List(api.ListOptions{})
if err != nil {
panic(err.Error())
}
fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))
time.Sleep(10 * time.Second)
}
}
func (inClusterClientConfig) ClientConfig() (*rest.Config, error) {
return rest.InClusterConfig()
}